Although the subject matter of Poe's story is a murder, "The Cask of Amontillado" is not a tale of detection; there is no investigation of Montresor's crime and the criminal himself explains how he committed the murder. The mystery in "The Cask of Amontillado" is in Montresor's motive for murder. Is it the search for wealth or revenge? Without a detective in the story, it is up to the reader to solve the mystery.